Thermotropic Copolyesters Based on Polyethylene Terephthalate and 4-Hydroxybenzoic Acid for High Modulus Fibers

2021 ◽  
Vol 887 ◽  
pp. 3-9
Author(s):  
T.R. Deberdeev ◽  
A.I. Akhmetshina ◽  
S.V. Grishin
Keyword(s):  
Dimethyl Ester ◽  
Hydroxybenzoic Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Polymer Backbone ◽  
Molecular Compounds ◽  
Anisotropic Phase ◽  
Thermal Stability Of ◽  
Thermotropic Copolyesters

The copolyesters derived from dimethyl ester of terephthalic acid, ethylene glycol, and 4-hydroxybenzoic acid (HBA) have been synthesized via catalytically promoted polycondensation omitting the acetylation step. FTIR spectroscopy results have evidenced an insertion of HBA along a polymer backbone. Of note, thermal gravimetric analysis has shown that the HBA moieties substantially improved the thermal stability of polyesters. As found by differential scanning calorimetry and polarizing microscopy, the copolyesters are capable of forming an anisotropic phase in a temperature range of 150-170 °C. Additionally, the free surface energy of the samples was determined to evaluate the compatibility of thermotropic copolyesters with other high-molecular compounds.

scholarly journals Effect of Sr2TiMnO6 fillers on mechanical, dielectric and thermal behaviour of PMMA polymer

2015 ◽  
Vol 05 (03) ◽  
pp. 1550018 ◽  
Author(s):  
P. Thomas ◽  
B. S. Dakshayini ◽  
H. S. Kushwaha ◽  
Rahul Vaish
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Thermo Gravimetric Analysis ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Transition Formula ◽  
Thermal Stability Of ◽  
Pmma Polymer

Composites of poly(methyl methacrylate) (PMMA) and [Formula: see text] (STMO) were fabricated via melt mixing followed by hot pressing technique. These were characterized using X-ray diffraction (XRD), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), thermo mechanical analysis (TMA) and impedance analyser for their structural, thermal and dielectric properties. The coefficient of thermal expansion (CTE) was measured between 40°C and 100°C for pure PMMA is 115.2 ppm/°C, which was decreased to 78.58 ppm/°C when the STMO content was increased to 50 wt.% in PMMA. There was no difference in the glass transition ([Formula: see text]) temperature of the PMMA polymer and their composites. However, the FTIR analysis indicated possible interaction between the PMMA and STMO. The density and the hardness were increased as the STMO content increased in the PMMA matrix. Permittivity was found to be as high as 30.9 at 100 Hz for the PMMA+STMO-50 wt.% composites, indicating the possibility of using these materials for capacitor applications. The thermal stability of polymer was enhanced by incorporation of STMO fillers.

Synthesis and characterization of diaminomaleonitrile-functionalized polystyrene grafts for application in pervaporation separation

2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Hamada Abdel-Razik
Keyword(s):  
Chemical Structure ◽  
Thermal Characteristics ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Optimum Conditions ◽  
Scanning Calorimetry ◽  
Phenol Water ◽  
Pervaporation Separation ◽  
Thermal Stability Of

AbstractSynthesis, characterization and application of diaminomaleonitrile (DAMN)-functionalized polystyrene grafts were studied. Dibenzoyle peroxide (BP) was used as an initiator. Optimum conditions for grafting were found to be c(DAMN) = 0.5 M, c(BP) = 0.016 M, θ = 85 °C and t = 4 h. Water uptake of the polystyrene graft membranes was found to increase with the increase of the grafting yield. The chemical structure, thermal characteristics and thermal stability of the obtained membranes were investigated by means of FTIR spectroscopy, differential scanning calorimetry, and thermal gravimetric analysis. Polystyrene graft membrane with the degree of grafting of up to 96 % was found to be useful for the pervaporation separation of phenol/water mixtures.

Halogenated sunflower oil as a precursor for synthesis of polysulfide polymer

e-Polymers ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Samira Moqadam ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Sunflower Oil ◽  
Proton Nuclear Magnetic Resonance ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir ◽  
Harsh Conditions ◽  
Thermal Stability Of ◽  
Polysulfide Polymer

AbstractPolysulfide polymers usually are prepared by the reaction of different dihalide compounds with disodium polysulfides. In this field, dihalides are expensive and produced from halogenation of organic compounds by different methods with harsh conditions. To overcome this problem, in this work, sunflower oil as polyunsaturated oil was used as precursor to produce polyhalide compound. In this field, double bonds of oil were applied as functional groups to halogenate the sunflower via benzoyl peroxide-catalyzed reaction with hydrochloric acid. Also, Na2S3 was synthesized via the reaction between sulfur and sodium hydroxide. Then, halogenated oil was reacted with Na2S3 to produce sunflower oil-based polysulfide polymer. Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H NMR) were used to characterize the structure of sunflower oil and synthesized polysulfide polymer. The content of halogenation was also obtained via energy-dispersive X-ray spectroscopy (EDX). Thermal stability of synthesized polymer was determined by means of thermal gravimetric analysis (TGA) and glass transition temperature was investigated by differential scanning calorimetry (DSC).

Experimental Investigation of Kevlar KM2Plus Nano-Reinforced Laminated Composite Thermo-Mechanical Properties

2016 ◽  
Author(s):  
Abdel-Hamid I. Mourad ◽  
Omar G. Ayad ◽  
Ashfakur Rahman ◽  
Ali Hilal-Alnaqbi ◽  
Basim I. Abu-Jdayil
Keyword(s):  
Mechanical Properties ◽  
Thermo Gravimetric Analysis ◽  
Laminated Composite ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Three Point Bending ◽  
Multi Walled Carbon Nanotube ◽  
Thermal Stability Of

This work is concerned with the synthesis and characterization of Multi-Walled Carbon Nanotube (MWCNT) reinforced Kevlar KM2Plus composites with various MWCNT contents (0.2, 0.3, 0.4, 0.5, 0.6, and 0.8 wt. %), by the wet lay-up technique. These samples were experimentally investigated for their thermo-mechanical properties using Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), tensile testing and three-point bending techniques. The mechanical properties showed remarkable improvement with increasing MWCNT wt.% up to certain content. The results revealed that the addition of MWCNT fillers has no significant effect on the thermal stability of the composites.

Polymer nanocomposites reinforced with C60 fullerene: effect of hydroxylation

2011 ◽  
Vol 45 (25) ◽  
pp. 2595-2601 ◽  
Author(s):  
Tsuyoshi Saotome ◽  
Ken Kokubo ◽  
Shogo Shirakawa ◽  
Takumi Oshima ◽  
H. Thomas Hahn
Keyword(s):  
Thermal Stability ◽  
Thermo Gravimetric Analysis ◽  
Nanocomposite Films ◽  
Light Transmittance ◽  
C60 Fullerene ◽  
Partial Hydrolysis ◽  
Poly Vinyl Alcohol ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

Novel nanocomposite films of polycarbonate (PC) with fullerene derivatives, such as pristine fullerene C60 and polyhydroxylated-fullerenes, C60(OH)12 and C60(OH)36, were prepared. The optical, thermal, and mechanical properties of the composites were measured. Nanocomposite films of poly (vinyl alcohol) (PVA) with C60(OH)36 were prepared as a reference to show how improved dispersion of the nanofiller affects the overall transparency of the composites. Ultraviolet-visible spectroscopy showed that the addition of hydroxylated fullerenes did not affect visible light transmittance of the films significantly in the range of 400–800 nm. Differential scanning calorimetry (DSC) and thermo–gravimetric analysis (TGA) measurements showed the increased thermal stability of PC/C60(OH)12 film as compared to pristine PC film. This phenomenon was explained by the rigid polymer interphase regions formed around C60(OH)12 due to the plausible hydrogen bonding and hydrophobic interaction. On the other hand, the lower thermal stability of PC–C60(OH)36 was assumed to be caused by large agglomeration of the C60(OH)36 particles and the partial hydrolysis of the polycarbonate matrix. Tensile testing of the composites showed reduction in elongation at break and yield tensile strength. These results may be caused by the particle agglomerations which act as the initiation points for cracks.

Fabrication of Magnetic Cenosphere Deposited with Fe3O4 Nanoparticles by Hydrothermal Method

2013 ◽  
Vol 750-752 ◽  
pp. 2021-2025 ◽  
Author(s):  
Hui Zhang ◽  
Jie Yao Song ◽  
Jian Chao Zhan
Keyword(s):  
Electron Microscope ◽  
Spinel Phase ◽  
Gravimetric Analysis ◽  
Vibrating Sample Magnetometer ◽  
Hydrothermal Conditions ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Reaction Solution ◽  
Average Size ◽  
Thermal Stability Of

We prepared the magnetic cenospheres deposited with magnetite Fe3O4nanoparticles under hydrothermal conditions. The crystalline phase, magnetization properties, morphology, chemical composition and thermal stability of asobtained cenospheres are analyzed by Xray diffraction, vibrating sample magnetometer, scanning electron microscope, Xray energy dispersive spectroscope, transmission electron microscope, thermal gravimetric analysis and differential scanning calorimetry techniques. The results show that the inverse cubic spinel phase of Fe3O4nanoparticles with an average size 50 nm are synthesized, and synchronously deposited on cenosphere surface. As the thickness of Fe3O4coating increases, the saturation magnetization increases to some extent. The growth of Fe3O4nanoparticles can be controlled by adding ethanol to the reaction solution.

scholarly journals An Investigation on the Comprehensive Property Assessment and Future Directions of Single Bamboo Fiber Reinforced Polypropylene Composites Fabricated by a Non-Woven Paving and Advanced Molding Process

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2641 ◽  
Author(s):  
Tang ◽  
Wang ◽  
Wang ◽  
Cheng ◽  
Guo
Keyword(s):  
Thermal Stability ◽  
Impact Strength ◽  
Water Resistance ◽  
Decomposition Temperature ◽  
Modulus Of Rupture ◽  
Gravimetric Analysis ◽  
Molding Process ◽  
Scanning Calorimetry ◽  
Bamboo Fibers ◽  
Thermal Stability Of

The demand for eco-friendly renewable natural fibers has grown in recent years. In this study, a series of polypropylene-based composites reinforced with single bamboo fibers (SBFs), prepared by non-woven paving and a hot-pressing process, were investigated. The influence of the content of SBF on impact strength, flexural strength, and water resistance was analyzed. The properties of the composites were greatly affected by the SBF content. Impact strength increased as SBF content increased. The modulus of rupture and modulus of elasticity show an optimum value, with SBF contents of 40% and 50%, respectively. The surface morphology of the fractured surfaces of the composites was characterized by scanning electron microscopy. The composites showed poor interfacial compatibility. The water resistance indicates that the composites with higher SBF contents have higher values of water absorption and thickness swelling, due to the hydrophilicity of the bamboo fibers. The thermal properties of the composites were characterized by thermal gravimetric analysis and by differential scanning calorimetry. The thermal stability of the composites was gradually reduced, due to the poor thermal stability of SBFs. In the composites, the maximum decomposition temperature corresponding to SBF shows an increasing trend. However, the maximum decomposition temperature of polypropylene was not influenced by SBF content. The melting point of the polypropylene in the composites was lower relative to pure polypropylene, although it was not affected by increasing SBF content.

scholarly journals The Effect of Ultrasonic Treatment on Thermal Stability of the Cured Epoxy/Layered Silicate Nanocomposite

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
N. Y. Yuhana ◽  
S. Ahmad ◽  
A. R. Shamsul Bahri
Keyword(s):  
Thermal Stability ◽  
Ultrasonic Treatment ◽  
Binary Systems ◽  
Layered Silicate ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Mechanical Stirring ◽  
Transmission Electron ◽  
Cloisite 30B ◽  
Thermal Stability Of

The effect of ultrasonic treatment on thermal stability of binary systems containing epoxy and organic chemically modified montmorillonite (Cloisite 30B) was studied. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and wide angle X-ray diffraction (WAXD) analysis were utilized. The mixing of epoxy and Cloisite 30B nanocomposites was performed by mechanical stirring, followed by 1 or 3-hour ultrasonic treatment, and polyetheramine as the curing agent. Both XRD and TEM analyses confirmed that the intercalation of Cloisite 30B was achieved. Thed0spacings for silicate in cured sample prepared at 1- and 3-hour duration of ultrasonic treatment were about 21 and 18 Å, respectively. This shows that shorter duration or ultrasonic treatment may be preferable to achieve higherd0spacing of clay. This may be attributed to the increase in viscosity as homopolymerization process occurred, which restricts silicate dispersion. The 1-hour sonicated samples seem to be more thermally stable during the glass transition, but less stable during thermal decomposition process.

scholarly journals Nonisothermal Cold Crystallization Kinetics of Poly(lactic acid)/Bacterial Poly(hydroxyoctanoate) (PHO)/Talc

2019 ◽  
Vol 17 (1) ◽  
pp. 1266-1278
Author(s):  
Omaima Alhaddad ◽  
Safaa H. El-Taweel ◽  
Yasser Elbahloul
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Crystallization Kinetics ◽  
Crystallization Rate ◽  
Cold Crystallization ◽  
Poly Lactic Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Kinetics Of ◽  
Thermal Stability Of

AbstractThe effects of bacterial poly(hydroxyoctanoate) (PHO) and talc on the nonisothermal cold crystallization behaviours of poly(lactic acid) (PLA) were analysed with differential scanning calorimetry (DSC), and the thermal stability of the samples was observed with thermal gravimetric analysis (TGA). The modified Avrami’s model was used to describe the nonisothermal cold crystallization kinetics of neat PLA and its blends. The activation energies E for nonisothermal cold crystallization were calculated by the isoconversional method of Kissinger-Akahira-Sunose (KAS). The DSC results showed that the PLA/PHO blends were immiscible in the whole studied range, and as the PHO and talc content increased, the crystallization rate of PLA accelerated, and the crystallinity of PLA in the PLA samples increased. The values of the Avrami exponent indicated that the nonisothermal cold crystallization of the neat PLA and its blends exhibited heterogeneous, three-dimensional spherulitic growth. The E values were strongly dependent on PHO and talc. The TGA results showed that the presence of PHO and talc slightly influenced the thermal stability of PLA.

Effect of chemical treatment on thermal properties of bagasse fiber-reinforced epoxy composite

2017 ◽  
Vol 24 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Varun Mittal ◽  
Shishir Sinha
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chemical Treatment ◽  
Epoxy Composite ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Chemical Treatments ◽  
Bagasse Fiber ◽  
Thermal Stability Of

AbstractThe present paper deals with a study of the thermal properties of bagasse fiber (BF)-reinforced epoxy composites. BFs are subjected to untreated and chemical treatments with 1% sodium hydroxide followed by 1% acrylic acid at ambient temperature before the composites are made. The thermal stability of the components was studied by thermogravimetric analysis and differential scanning calorimetry, as well as by differential thermal gravimetric analysis. Thermal analysis results of untreated BF-reinforced epoxy composite were compared with treated BF-reinforced epoxy composite. The chemical treatment of BF induces reasonable changes in the thermal stability of the polymer composites.

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